Connection options for the PCB (SCU-S02)
If the boiler is fitted with the PCB (SCU-S02), then this PCB is automatical
ly recognised by the boiler's automatic control unit.
Note
On removing this PCB, the boiler will show error code
. To
prevent this error, an auto-detect must be carried out after remov
ing this PCB.
For information on carrying out an auto-detect, see: Carrying out an auto-
detect, page 51
The status indicator D3 at the top right of the PCB indicates the status:
Continuous signal: PCB working normally
Flashing signal: no connection
No signal: no power or faulty PCB (check the wiring)
Control of external CH pump (pump)
An external central heating pump can be connected to the pump terminals
of the connector. The maximum power consumption is 400 VA.
Control of external three-way valve (3wV)
The external three-way valve (230 VAC) can be used when connecting an
indirectly heated calorifier. The neutral position of the three-way valve can
be set using parameter
.
The three-way valve is connected as follows:
N = neutral
C = central heating
D = calorifier
Connecting external DHW pump (3wV)
It is also possible to connect an external DHW pump to the terminals 3wV.
Connect the pump as follows:
N = N pump
D = L pump
= PE pump
Caution
If the neutral position of the three-way valve is adjusted with pa
rameter
, the pump must be connected as follows:
N = N pump
C = L pomp
= PE pump
Control of external gas valve (EgV)
If there is a heat demand, an alternating voltage of 230 VAC, 1 A (maxi
mum) becomes available on the EgV terminals of the connector to control
an external gas valve.
Connecting the minimum gas pressure switch (Gps)
The minimum gas pressure switch blocks the boiler if the gas inlet pres
sure becomes too low.
1. Connect the minimum gas pressure switch to the Gps terminals of
the connector.
The presence of the gas pressure switch must be set using parameter
.
Connecting a heat recovery unit (Hru)
1. Connect the wires from the heat recovery unit to the Hru terminals of
the connector.
The presence of the heat recovery unit must be set using parameter
.
Fig.33 SCU-S02 PCB
AD-0000057-01
Status
C
Nc
No
C
Nc
No
Pump
N L
Pump
N
L
EgV
N L
EgV
N L
3wV
X3
SCU-SO2
X1
X4
X5
N C
3wV
N C D
D
X2
D3
Tsol
Gps
Tsol
Gps
Hru
Hru
F 4AT
6 Installation
123157 - v.06 - 24022015
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